Reigning BMX racing gold medalist Connor Fields of the United States was carried off on a stretcher and loaded into an ambulance after crashing in the third semifinal heat at the Tokyo Olympics on Friday.
Fields was fourth after his opening two heats and landed hard off a jump heading into the first turn in the third run. The 28-year-old from Las Vegas slammed into the turn and was hit by two other riders. Medical personnel rushed out to attend to Fields, who lay on the track for several minutes before being carried to an ambulance.
Fields qualified for the finals based on his first two heats but wasn't able to ride.
USA Cycling said in a statement that Fields was awake and awaiting further evaluation at the hospital.
Fields became the first American BMX rider to win gold at the 2016 Rio Games and was a favorite to win it again in Tokyo. He also was involved in a scary crash in 2018 that nearly ended his career.
Niek Kimmann of the Netherlands won Friday's men's event, edging Kye Whyte of Britain at the finish line. Carlos Ramirez Yepes of Colombia took bronze.
Kimmann, who also suffered a scary crash as the Olympics began when he collided with a race steward who had wandered onto the track during training, gave the Netherlands its first gold medal in BMX racing.
"This week has been an emotional roller coaster," said Kimmann, who injured his knee in the incident. "The crash with the official, I thought my week was over, basically. But after getting the MRI results, we realized it would be possible. It wouldn't be comfortable, but it was possible."
In the women's race, Bethany Shriever of Britain ended Mariana Pajon's bid for a third straight Olympic gold medal, pulling away from the Colombian to win.
Shriever jumped to an early lead and held off Pajon at the finish in her first Olympics. Dutch rider Merel Smulders took bronze.
Pajon became the first rider to win two BMX racing gold medals with her victory at the 2016 Rio de Janeiro Olympics.
American Alise Willoughby, among the gold-medal favorites, crashed in the first and third heats to miss qualifying. She tangled in the second crash with Australian Saya Sakakibara, who was taken off on a stretcher.
Information from The Associated Press was used in this report.